Self-operating door and hinge



-- gum;

Nov. 1, 1960 R. K. NOTTINGHAM 2,958,091

SELF-OPERATING DOOR AND HINGE 4 Sheets-Sheet 1 Filed April 22, 1957 INVENTOR. RALPH K. NOTTINGHAM Nov. 1, 1960 R. K. NOTTINGHAM SELF-OPERATING DOOR AND HINGE 4 Sheets-Sheet 2 Filed April 22. 1957 \JKJ INVENTOR. FIG'8 RALPH K. NOTTINGHAM A TTO PNEKS' Nov. 1, 1960 R. K. NOTTINGHAM SELF-OPERATING DOOR AND HINGE 4 Sheets-Sheet 3 Filed April 22. 1957 FlG.ll

FIG. IO

INVENTOR. RALPH K- NOTTINGHAM A T TORNE KS Nov. 1, 1960 R. K. NOTTINGHAM SELF-OPERATING DOOR AND HINGE 4 Sheets-Sheet 4 Filed April 22, 1957 FIG.|2

FIG. l4

FIG. l5

IN VEN TOR.

T w W N $0 K. MW H A P AY RB 2,958,091 SELF-OPERATING noon AND HINGE Ralph Kenneth Nottingham, 2934 NE. 51st Ave,

Portland, Greg.

Filed Apr. 22, 1957, Set. No.654,107

8 Claims. (Cl. 16-156) My present invention relates to hinge constructions and has for its principal object the provision of means whereby a door which has been opened to a certain extent will continue swinging to a fully open position at which it remains, and vice versa. The invention is of utility in connection with any type of horizontally swinging door or other closure, including cabinet doors, walkin cooler doors, farm gates, and the like. A door mounted in accordance with my invention will remain closed when placed in a closed position without the use of latches, catches, springs, and other devices normally employed to hold a door closed, and will likewise remain in an open position when so positioned. The hinge of the present invention may assume a wide variety of shapes and forms without departing from the invention, and may be employed in combination with doors which over-lap the opening which is closed thereby, or which fit flush within the opening closed thereby.

The objects :and advantages of the present invention will be more readily understood by reference to the following specification taken in connection with the accompanying drawings wherein like numerals refer to like parts throughout.

In the drawings:

'Fig. 1 a view of a cabinet and overlapping door, partly broken away, with the door mounted by means of a preferred form of the hinge of the present invention; 7 p I i Fig. 2 is a horizontal section taken substantially along line 2-2 of Fig. l and showing the door closed; 7

Fig. 3 is a view similar to Fig. 2 showing the door partially opened;

Fig. 4 is a horizontal section taken substantially along line 4-4 of Fig. 1 and showing the door closed;

Fig. 5 is a similar view showing the door partially opened;

Fig. 6 is a horizontal section taken substantially along line 6--6 of Fig. 1 with the door and connected portions of the hinge removed;

Fig. 7 is a force-motion diagram explaining the operation of the door hinges illustrated in Figs. 1 to 6;

Fig. 8 is a similar diagram in explanation of a modified shape of hinge; v

Fig. 9 is a similar diagram explaining the action of various shapes of hinges between the limits of maximum and minimum sizes permissible for a portion of the hinge construction;

Fig. 10 is a force diagram illustrating the action of a minimum size of construction; 7

Fig. 11 is a force diagram explaining a further modification of the hinge shape; I V v Fig. 12 is a partial horizontal section through a walkin cooler employing a modification of the present invention;

Fig. 13 is a partial view in elevation illustrating amodidoors for walk-in coolers or other heavy doors;

itef States Patent 0 fied hinge such as might be employed in connection with Fig. 14 is a view in elevation illustrating the application of the present invention to a farm gate;

, Fig. 15 is a partial verticalsection illustrating the ap plication of the present invention to a flush cabinet door;

Fig. 16 is a partial view in elevation illustrating a further modification of the present invention; and

Fig. 17 is a horizontal section on an enlarged scale taken along line 17--17 of Fig. 16.

Figs. 1 to 6, inclusive, illustrate a preferred form of the invention which would have utility in connection with small cabinet doors. In the drawings the cabinet 10 is provided with an access opening 11 which is closed by an overlapping door 12, the door being slightly wider and higher than the opening so as to overlap the edges thereof on all sides. The door is mounted by means of an upper hinge 13 and a lower hinge 14 which, while having the same general characteristics, differ in some details as will appear.

The upper hinge 13 comprises a door mounting portion 16 which is fastened to the outer face of and adjacent a vertical edge of the door by a pair of screws 17. Preferably, the mounting portion is angular so that a part thereof overlies the outer face of the door and a portion thereof overlies the vertical edge of the door. By reason of this construction no mortising or in-letting of the hinge is necessary, and the hinge can be quickly mounted upon adoor comprising a board or rectangular sheet of plywood. A pair of arms 18 extend laterally from the mounting portion 16 at the upper and lower edges thereof. It can be seen that the mounting portion 16 and the arms 18 are integral and comprise a unit which is easily stamped from a sheet of metal and bent to shape. The arms are wide, but slightly narrower than the thickness of the door. At the extremities the arms are connected together by a pair of spacer rivets 20 at the outer corners of the arms, which rivets extend vertically in spaced, parallel relation in a plane normal to the face of the door. Each rivet acts as an axle for a nylon tube roller 21 which coaxially surrounds the axle and is freely rotatable thereon.

The rollers 21 extend vertically through a retaining sleeve 23 extending outwardly from a mounting plate 24 which is retained on the cabinet by screws 25. The retaining sleeve 23 is easily provided integrally with the mounting plate 24 by stamping the plate and a pair of laterally projecting, central portions from a sheet of metal, bending the two portions into the desired shape and connecting their end edges together as at 26 by welding, brazing, soldering or the like. The retaining sleeve 23 is mounted vertically and surrounds the rollers 21, and is embraced by the horizontal arms 13 so that the two relatively movable portions of the hinge, one connected to the door and the other connected to the cabinet, are permanently engaged with each other.

The lower hinge 14 comprises a similar construction, including a door mounting portion 30 which is mounted upon the door 12 by :a pair of screws 31 and integral, laterally projecting arms 32 which are connected together at their outer ends by a pair of vertical spacer rivets 33 forming axles for a pair of nylon tube rollers 34. The rollers are retained ina retaining sleeve 35 formed'by integral portions of a mounting plate 36 connected together at their end edges at 37. The-mounting plate is 3 line parallel to the vertical edges of the door, as indicated in Fig. 6.

The door is supported by the inner roller 21 bearing against the side of the sleeve 23 adjacent the door, and the outer roller 34 bearing against the side of the retaining sleeve 35 away from the cabinet, when the door is closed. The door is supported when it is swung open to 90 by both of the rollers 21 hearing against the outer side of the retaining sleeve 23 and both of the rollers 34 bearing against the inner sideof the retaining sleeve 35. For this reason the arms 18 are shorter than the arms 32 by the amount necessary to so position the upper and lower rollers against relatively opposite sides of the retaining sleeves.

In order to reduce friction the lower arms 32 mount a rivet 40 which extends through the arms 32 and below the lowermost one thereof toward a shelf 41 projecting outwardly from the mounting plate 36. A nylon tube thrust bearing 42 surrounds the lower projecting end of the rivet 40 to space the lower arm 32 from the shelf 41 by an amount sufficient to raise the upper arms 32 and 18 from the upper edges of the retaining sleeves.

It will be observed that in this preferred form of the invention the rollers 21 of the upper hinge are substantially tangential to the bases of the isosceles trapezoid retaining sleeve on the door side of the center line of the sleeve when the door is closed, and the rollers 34 are substantially tangential to the bases of the isosceles trapezoid retaining sleeve 35 on the side away from the door when the door is closed. Because of the sloping sides of the retaining sleeves only the inner roller 21 contacts the adjacent sloping side of the sleeve 23, and only the outer roller 34 contacts the farther sloping side of the sleeve 35 when the door is closed. The wide base of each of the sleeves is of such dimension that the rollers may lie tangentially against the same when the door is opened to 90, the rollers 21 being held against the outer base of the upper sleeve 23 and the rollers 34 being held against the inner base of the lower sleeve 35 by the weight of the door. When the door is in its open position, the rollers are firmly retained by the sloping sides of the sleeves so that if a person should attempt lifting the outer edge of the door the sleeves would resist. Movement of the door is thus restricted to swinging in a substantially horizontal plane in the natural manner of doors.

Fig. 7 is a schematic force-motion diagram, with the upper hinge being superimposed upon the lower hinge. The isosceles trapezoid ABCD represents the inner surface of the upper sleeve 23. The reversed isosceles trapezoid EFGH represents the inner surface of the lower retaining sleeve 35. The upper rollers 21 are drawn in solid, heavy lines in the positions they occupy when the door is closed, with their centers at I and I. When the door is swung open the inner roller 21 rolls along the surface of the side AB with its center moving along the line IK as indicated by the double line straight arrow. At the same time the outer roller 21 rolls along the surface BC with its center moving from I to L as indicated by the single line straight arrow. The locus of the upper rollers moves from the point M when the door is closed along the curved double line arrow to the point N. At the same time the outer, lower roller 34 rolls along the surface of the side GH of the lower strap 35 with its center moving from the point to the point P, as indicated by the dashed, double line, straight arrow. Simultaneously, the inner, lower roller 34 rolls along the side HE with its center moving from point Q to point R, as indicated by the single dash line, straight arrow. The locus of the lower rollers simultaneously moves from point S to point T, as indicated by the curved double line arrow. As long as the slope of lines tangential to the curves MN and ST remains less than 45 the door will tend to swing shut, but when the slope of the tangential lines exceeds 45 the door will tend to swing open to a position at right angles to the face of the cabinet. This transition from closing tendency to opening tendency occurs when the angle between the door and the cabinet is about 40; however because of friction the door will remain angularly open in the region of about 35 to 45 swinging shut when it is at or less than 35 and swinging open when it is at or more than 45 As the door swings open from a closed position to the transition point the outer edge of the door is lifted a fraction of an inch, and as it swings from the transition point to the resting point at to the cabinet the outer edge of the door lowers until the upper edge of the door again reaches substantially the horizontal, as it was in the closed position. It is this elevating of the outer edge of the door which gives the force to hold the door closed or open. The amount of force is a function of the movement horizontally toward or away from each other of the loci of the rollers during the swinging motion, the vertical Separation of the upper and lower hinges, and the width and weight of the door.

Fig. 8 is a motion-force diagram illustrating the fact that the hinge would be operative if the sleeve were square, with its sides tangential to the rollers. In this diagram the upper rollers move from A to B and from B to C, respectively, in the directions of the arrows when the door is swung from closed to open position. The locus of the upper rollers moves along the true arc DB in the direction of the arrow. Simultaneously, the lower rollers move respectively from C to F and from F to A in the directions of the arrows, with the locus thereof moving along the true are GH. The transition from opening to closing forces occurs at 45. The door would hang level and be held closed by the maximum force possible, and it would hang at the same level and be held open at 90. However, this form of hinge is less desirable since, when the door is closed, or when it is open, its outer edge may be lifted angularly with respect to the cabinet because there is no restraining effect such as caused by the tapering sides of the isosceles trapezoid sleeves of the preferred form. Fig. 7 is complete in that the motions of the rollers and loci are illustrated for movement of the door from 90 to 180 illustrating forces tending to swing the door to a 90 position when it is opened to less than and to a position when it passes the second transition point at 135 Fig. 9 is a schematic force-motion diagram in which the upper hinge only is illustrated, but it is to be appreciated that the lower hinge could be superimposed in reverse as it is in Figs. 7 and 8. This diagram analyzes the effect of changing the slope of the sides of the isosceles trapezoid sleeves, and also of curving them. In the diagram the solid line trapezoid ABCD represents substantially the same figure as illustrated in Fig. 7, but with less slope to its sides. The locus of movement of this construction is indicated by the solid line curve EF. The dash-dot line BG represents the side of a square sleeve, as illustrated in Fig. 8, and the movement of the locus in this instance is represented by the dash-dot line HF along a true are. If the sides of the sleeve were curved substantially along the dash-circle line BI the path of movement of the locus would be along the dashcircle line JF, and if the sleeve were further constricted along the curved dash line BK the movement of the locus would be along the dash line LP. The sloping side line MN illustrates the fact that substantially the minimum acceptable figure is represented by the curved dash line BK for the reason that the straight side MN, at a slope of substantially 65, would hold the hinge practically immobile, because the shortest distance between the point 0, which is the center of a roller jammed in the angle MQR, and the line MN is less than the distance from the center of one roller diametrically to the outer surface of 5 the other roller. However, the curved dash line BK, which at all points is, at a distance equal to, or slightly greater than, the distance from the point diametrically through the other roller to the outer surface thereof, represents an operative sleeve.

It will be noted that, in order for the minimum sleeve to be utilized, the rollers are all centered on the vertical center plane of the sleeve normal to the door, which means that with this minimum sleeve construction the length of the arms 18 would be equal to the length of the arms 32. It also follows that the difference in length of the arms 18 and 32 is greatest when a square sleeve is utilized. Therefore, a square sleeve gives the greatest door lifting efieot and the minimum strap gives the least. Also, it is to be noted that the door will hang open at exactly the same level it occupies when it is closed only when a square sleeve is employed, and the more the sleeve is constricted the greater the door will sag open at 90. To illustrate the extreme, when the arms are of the same length both the upper and lower rollers are centered along the vertical center line FP of the sleeve (Fig. 9) when the door is closed, and the loci thereof would be at the point L in both the upper and lower hinges. However, when the door swings open to 90 the upper locus will be established at F and the lower locus will be established at P. Therefore, the door will sag in an open position by a function of the distance FP, the vertical separation of the hinges, and the horizontal Width of the door. Also there would be no force to hold the door closed. Therefore, while the minimum sleeve is op erable in a way, it is not desirable, and the best results are obtained with an isosceles trapezoid slightly less than the square, with the sides sloping at an angle of about to 10. These sides may be curved slightly, if desired, without departing from the optimum condition.

To summarize, a square sleeve gives good force for opening or closing the door, but the door may be lifted about its hinges. An isosceles trapezoid with a slight slope to its sides is the optimum sleeve since the opening or closing force is near the maximum, the sag of the door when open is so slight as to be unnoticed, and the constriction of the sides prevents lifting the door about its hinges. The minimum sleeve, while it may be operable to permit the door to swing, is undesirable, since the closer the arms approach equality in length the closer the transition point approaches 0, so that there is practically no force tending to hold the door closed and it would rattle against the cabinet with vibrations or breezes, and the door would sag open to a maximum and noticeable extent. Therefore, from all considerations the preferred construction comprises an isosceles trapezoid with the sides sloping in the range of 5 to 10".

Fig. 10 is a force-motion diagram illustrating the absolute minimum sleeve, having a flat base A and curved sides B and C. With such a strap the arm lengths would be equal. The inner roller of the upper pair in moving from closed to 90 position would move along the curved path from D to E, simultaneously the outer roller would move along the straight path from F to G, and the locus of the rollers would move along the path H to F. Such a minimum strap, while operative, has the undesirable features noted above, but nevertheless comes within the scope of the invention.

Fig. 11 represents a permissible sleeve in the form of an isosceles triangle. With this construction the arms would have to be equal again, and the rollers would move as follows: The inner, upper roller would move from the point A to the point B while the outer roller would move from the point C at least to the point D. However, when the two rollers are tangential to the base FG of the triangle neither roller would be jammed in a corner, with the result that the center of one roller could rattle from point B to point H and the other roller would correspondingly move from point D to point I. Therefore, an isosceles triangle, while permissible, would have the undesirable features of no force tending tov hold the 6 door closed, the door being unstable and rattling. with breezes and vibrations when open at and the door sagging to a maximum extent when open at 90.'

It is to be appreciated that a number of force-motion diagrams, but really only one modification of the invention, have been discussed, i.e. a pair of vertical rollers. mounted in a retaining sleeve which may vary between maximum and minimum limits. A point which is thus brought out is that the hinge need not be manufactured to precision tolerances, since variations will still be operable. And the further point is brought out that for a number of reasons an isosceles trapezoid with, slightly sloping sides is the optimum form.

Figs. 12 and 13 on the other hand, illustrate a modification. The invention is therein shown in connection with a walk-in cooler 50 having insulated walls, a door opening 51, and a heavy, insulated door 52.. The door is mounted on a pair of hinges, as previously described, only the lower hinge being herein illustrated. The hinges preferably comprise the optimum shaped sleeve, as previously described, each comprising a door mounting portion 53 having arms 54 mounting a pair of vertical rollers 55. The rollers are retained in an isosceles trapezoid retaining sleeve 56 extending outwardly from a mounting plate 57 fixed to the wall of the cooler. In this instance a wheel clevis 60 extends downwardly from the lower arm of at least one of the hinges and mounts a wheel 61 which rolls on a supporting shelf 62 projecting outwardly from the mounting plate 57. By using the preferred form of sleeve the door is firmly urged toward closed position. The door preferably presses against a door sealing gasket 63 surrounding the door opening 51. This construction is highly desirable in that there is no need for latches and catches to hold the door firmly closed, and a person inside the cooler may open it simply by pressing against the door. This construction is of extreme importance since, while cooler door latches must be provided with safety devices to permit the latch to be operated from the inside, there have nevertheless been unfortunate instances of children and even adults being trapped in coolers.

Fig. 14 illustrates the same construction as described in connection with Figs. 12 and 13, with a different use of the hinge. In this figure a fence gate 70 is mounted upon an upper hinge 71 and a lower hinge 72 as previously described, the hinges being mounted upon a gate post 73. The gate is held firmly against the opposed gate post 74 but will be retained in open position at 90 to the fence when it is swung open. The point of transition is the same as previously described. The gate is of value in that a pedestrian or horseman may squeeze through the gate without manipulating any latch and the gate will automatically swing shut behind him, but farm animals would not have the intelligence to open the gate in one direction. On the other hand, a vehicle driver may bump the gate open from the other direction and it will swing to an open position and remain there until closed. At least to a certain extent, the gate serves all purposes of farm gates and eliminates some of the difficulties of operating them.

Fig. 15 illustrates the same hinge, except for a change in the form of the door attaching portion. This view illustrates a cabinet front 86 having an access opening 81 which is closed by a flush door 82. The door is hinged by means of upper and lower hinges, just as previously described. The lower hinge 83 is shown, with the shape of the door mounting portion being changed so that no portion thereof overlies the face of the door. Such a change is merely a change in ornamental appearance, not in basic structure or operation. This view illustrates the fact that, by relieving the outer edge of the door and in-letting the hinges in thedoor edge, the hinges may be utilized to mount tight, flush doors.

Fig. 16 illustrates a modification representing the minimum in refinement of the invention. In this figure a door 90 is illustrated as being mounted upon a cabinet 91 by means of upper and lower hinges comprising isosceles trapezoid sleeves 93 and 94 in relatively reversed relation, as previously described. In this instance, the rollers and roller mounting arms have been replaced by simple, short angle bars 95 and 96, each with a horizontal leg connected to the door and its vertical leg turned downwardly and extending into the retaining sleeve. The sleeve is merely a rod bent to the desired polygonal form and welded to the mounting plate 97. The vertical edges of the downwardly extending portions of the angle bars 95, 96 act as the opposed outer surfaces of the pairs of rollers. There is no thrust bearing provided, the angle bars merely resting upon the upper edges of the sleeves. With reference to Fig. 17 it will be observed that the angle bars 95, 96 have a width which is substantially equal to the distance between the bases of the trapezoidal sleeve 93 and that the width of the bar 95 is greater than the distance between the walls of the sleeve adjacent its small base, that is, adjacent the mounting plate 97, but is of substantially the same length as the distance between the larger base of the Sleeve. Such an inexpensive construction will operate firmly to hold the door closed or open at 90. By lubricating the contacting portions of the angle bars 95, 96 and the sleeves the operation of the door may be rendered fairly easy; but, obviously, friction will be high and the door might not automatically swing shut from a narrow angle such as in the excess of 20 and might not automatically swing open until it passes a wide angle in the range of 70.

It is to be appreciated that the rollers herein described have been described as comprising sections of nylon tube. This material is hard and durable and does not require lubrication, yet operates almost noiselessly. Nevertheless, any suitable material may be utilized for the rollers, such as steel rollers in the case of heavy doors as illustrated in Figs. 12 and 13.

Having illustrated and described several modifications of my invention, it should be obvious to those skilled in the art that the same permits of further modification in arrangement and detail. I claim as my invention all such modifications as come within the true spirit and scope of the following claims.

I claim:

1. A hinge comprising a rigid retaining sleeve having an isosceles trapezoid cross section, said sleeve comprising a long base wall, a short base wall and side walls of equal length, means to mount said sleeve upon a supporting structure with said base walls and side walls extending vertically, said sleeve being open at the top, a cooperating hinge part comprising means to mount said hinge part upon a door and an arm extending from said means over the upper edge of said sleeve, said arm terminating in a portion extending vertically downward into said sleeve, said portion having a major axis in cross section substantially equal to the distance in cross section normal to said base walls and a minor axis in cross section substantially less than said distance, said long base wall having a length greater than said distance and said short base wall having a length less than said distance, whereby said portion may fit snugly between the base walls of said sleeve when disposed crosswise of said sleeve with its major axis of cross section normal to said base walls and may fit snugly between the side walls of the sleeve with its major axis of cross section parallel to said base walls only when lying against said large base wall.

2. A hinge comprising a rigid retaining sleeve, means to mount said sleeve vertically upon a supporting structure, a cooperating hinge part comprising a vertically extending portion fitting snugly within said sleeve and capable of turning therein through an angle of at least 90, and means to mount said part upon a door, said vertically extending portion comprising a pair of upright rollers mounted side-by-side with their axes lying along a vertical plane normal to a vertical plane passing through the outer face of the door.

3. A hinge comprising a rigid quadrilateral retaining sleeve having opposed side walls, means to mount said sleeve vertically upon a supporting structure, a cooperating hinge part comprising a portion extending vertically into said sleeve and fitting snugly between opposed walls of said sleeve, and means to mount said part upon a door, said vertically extending portion comprising a pair of upright rollers mounted side-by-side with their axes lying along a vertical plane normal to a vertical plane passing through the outer face of the door.

4. A hinge comprising a rigid, isosceles trapezoid retaining sleeve having opposed bases and side walls, means to mount said sleeve vertically upon a supporting structure, a cooperating hinge part comprising a portion extending vertically into said sleeve, said portion fitting snugly between the opposed bases of said sleeve in one relative position and between the side walls of the sleeve only adjacent the large base thereof when turned within the sleeve, and means to mount said part upon a door, said vertically extending portion comprising a pair of upright rollers mounted side-by-side with their axes lying along a vertical plane normal to a vertical plane passing through the outer surface of the door.

5. Hinge means to mount a door upon a structure having an opening therein comprising an upper hinge and a lower hinge, said upper hinge comprising a rigid, vertical sleeve with open ends projecting outwardly therefrom, said lower hinge comprising a rigid, vertical sleeve with open ends projecting outwardly therefrom, said upper hinge also comprising a pair of rollers mounted vertically in side-by-side relation with their axes in a plane normal to the planes of the surfaces of the door, said lower sleeve also comprising a second pair of rollers mounted vertically in side-by-side relation with their axes in a plane normal to the planes of the surfaces of the door, upper arms connecting said upper pair of rollers to the door laterally adjacent a vertical edge thereof, and lower arms connecting said lower pair of rollers to the door laterally adjacent the same vertical edge of the door, said upper arms being shorter than said lower arms whereby said upper rollers are closer to the door than said lower rollers, said upper rollers projecting into said upper sleeve and said lower rollers projecting into said lower sleeve.

6. Hinge means to mount a door upon a structure having an opening therein comprising an upper hinge and a lower hinge, said upper hinge comprising a rigid, vertical, isosceles trapezoid sleeve having open ends, said lower hinge comprising a rigid, vertical, isosceles trapezoid sleeve having open ends, said sleeves being mounted on the structure in vertical alignment adjacent the opening, said upper hinge also comprising a pair of rollers mounted in side-by-side relation with their axes in a vertical plane normal to the plane of a surface of the door, said lower hinge also comprising a second pair of rollers mounted in side-by-side relation with their axes in a vertical plane normal to the plane of a surface of the door, upper supporting means connecting said upper pair of rollers to the door laterally adjacent a vertical edge thereof, and lower supporting means connecting said lowor pair of rollers to the door laterally adjacent the same vertical edge of the door, said upper supporting means being shorter than said lower supporting means whereby said upper rollers are closer to the door than said lower rollers, said upper rollers projecting into said upper sleeve and said lower rollers projecting into said lower sleeve.

7. Hinge means to mount a door upon a structure having an opening therein comprising an upper hinge and a lower hinge, said upper hinge comprising a rigid, vertical isosceles trapezoid sleeve having open ends and opposed side walls and bases, said lower hinge comprising a rigid, vertical, isosceles trapezoid sleeve having open ends and opposed side walls and bases, said sleeves being mounted on the structure in vertical alignment adjacent the opening, said upper hinge also comprising a pair of rollers mounted in side-by-side relation with their axes in a vertical plane normal to the plane of a surface of the door, said lower hinge also comprising a second pair of rollers mounted in side-by-side relation with their axes in a vertical plane normal to the plane of a surface of the door, upper supporting means connecting said upper pair of rollers to the door laterally adjacent a vertical edge thereof, and lower supporting means connecting said lower pair of rollers to the door laterally adjacent the same vertical edge of the door, said upper supporting means being shorter than said lower supporting means whereby said upper rollers are closer to the door than said lower rollers, said upper rollers projecting into said upper sleeve and said lower rollers projecting into said lower sleeve, said pairs of rollers snugly fitting between the bases of the respective sleeve in one relative position when the door is closed and snugly fitting between the sides of the respective sleeve only adjacent the large base thereof when the door is open, one of said sleeves having its larger base toward the structure and the other having its larger base away from the structure.

8. Hinge means to mount a door upon a structure having an opening therein comprising an upper hinge and a lower hinge, said upper hinge comprising a rigid, isosceles trapezoid sleeve having open ends and opposed side walls and bases, said lower hinge comprising a rigid, vertical, isosceles trapezoid sleeve having open ends and opposed side walls and bases, said sleeves being mounted on the structure in vertical alignment adjacent the opening, said upper hinge also comprising a pair of rollers mounted in side-by-side relation with their axes in a vertical plane normal to the plane of a surface of the door, said lower hinge also comprising a second pair of rollers mounted in side-by-side relation with their axes in a vertical plane normal to the plane of a surface of the door, upper supporting means connecting said upper pair of rollers to the door laterally adjacent a vertical edge thereof, and lower supporting means connecting said lower pair of rollers to the door laterally adjacent the same vertical edge of the door, said upper supporting means being shorter than said lower supporting means whereby said upper rollers are closer to the door than said lower rollers, said upper rollers projecting into said upper sleeve and said lower rollers projecting into said lower sleeve, said pairs of rollers snugly fitting between the bases of the respective sleeve in one relative position when the door is closed and snugly fitting between the sides of the respective sleeve only adjacent the large base thereof when the door is open, one of said sleeves having its larger base toward the structure and the other having its larger base away from the structure, and a thrust bearing means in one of said hinges for lifting said upper and lower supporting means from contact with said sleeves.

References Cited in the file of this patent UNITED STATES PATENTS 494,549 Clement Apr. 4, 1893 1,225,899 Weber May 15, 1917 1,232,225 Clements July 3, 1917 1,591,649 Stringfellow et al. July 6, 1926 1,793,946 McEwan Feb. 24, 1931 2,309,279 Smythe Ian. 26, 1943 

